A multilayer printed substrate in which a plurality of small-sized printed substrates are stacked on one another has been developed. This multilayer printed substrate includes small-sized printed substrates, and therefore there are a few terminals and the terminal positions are standardized. With this structure, between adjacent printed substrates, the terminals disposed at corresponding terminal positions cannot be used for different purposes.
Under these circumstances, there has been a demand of an interposer substrate and a multilayer printed substrate, which enable terminals arranged at corresponding terminal positions to be used for different purposes.